Glowworm Xtrafast - hw issue

[johno_uk]

Had the pleasure of visiting this piece of s&£t today. Went to fit a new plate hex, filling loop and prv that another engineer ordered. After fitting parts and pressurising, I switched on and ran the heating, no problems. As soon as the hw selector switch was turned up and boiler fired for hw the hw safety prv on the storage tank started ****ing out, which I assumed must be letting by? but as soon as hw dial turned down it stopped leaking (no fault codes). This happens every time hw is turned on? I had no mi's and was short on time so rang Glowworm tech and he reckons the pressure sensor must be faulty. I removed the sensor to give a quick clean and see if any debris then put back together. Still same problem so ordered one up and left.

having had time to think about it tonight I can't see how the water pressure sensor (as terrible as they are) would cause the hw storage to blow off yet be ok for the heating circuit?

Any thoughts????

 

[Rabbitman]

Try venting the dhw pump it may take a few goes,

 

[johno_uk]

Cheers rabbitman, I'll give that a go. There was a fair bit of air bled from the taps when water turned back on.